Question

Number average molecular mass and weight average molecular mass of synthetic polymers are related as?

• A. $M_w>1/2M_n$
• B. $M_w=M_n$
• C. $M_w>M_n$
• D. $M_w<M_n$

Answer 1

The correct option is C

$M_w>M_n$

For synthetic polymers, PDI > 1

This is because man-made polymers have a wide range of molecular chain lengths and weights, which increases their 'dispersity' in chain length and weight.

So, for man-made polymers, $M_w>M_n$

Proteins are usually mono-disperse, meaning that their chain lengths and molecular weights remain the same. So, PDI = 1.